1. Field
The present invention relates to coding of typographic characters, or more particularly, to a method and apparatus for representing each Chinese character using English letters as a reversible code, i.e. a one-code-one-character ideographic character coding.
2. State of the Art
Many coding methods of Chinese characters exist for inputting Asian characters and dictionary indexing. A Chinese character set is composed of a large number of ideographs that represent the characters in the Asian languages. An Asian language may include thousands of characters. For example, the set of the simplified Chinese characters used in Mainland China includes slightly over seven thousand distinct characters. These characters integrate both meaning and pronunciation information. They thus differ from the more purely phonetic writing systems of Western languages. Many consider Chinese characters as overly complex, but in fact they are all derived from a couple hundred simple pictographs and ideographs in ways that are usually quite logical and easy to remember. Keyboards with each key separately representing a Chinese character were bulky and extremely difficult to use. Present reform movements seek to introduce a phonetic alphabet, which would gradually replace Chinese characters in everyday use. However, until this occurs, there remains a need to key code these Chinese characters utilizing conventional keyboards to type and input data.
One conventional computer technique for coding Chinese characters in Asian languages uses the method of radical decomposition. One typical example is described in “Chan-Jei input method” by Acer Systems, Inc. (published by Zu-Lin book company in 1985). In this method, a Chinese character is represented as an ordered sequence of symbols using Chinese basic radical symbols where each symbol is patched upon an English letter on a keyboard randomly. Disadvantages associated with this method are:
First, there is a “collision” problem where one character code representation may correspond to more than one character, so that the produced code cannot be used for indexing.
Second, the limited number of radical symbols used requires a keyboard of special design, which results in unconventional typing input for users familiar with English typing methods.
Third, in order to solve the collision problem, the method requires an ergonometric design of man-machine interaction for the users to pick the desired character from the collided characters displayed on the screen, and thus is not user-friendly.
Fourth, the arrangement of the adopted radical symbols on the keyboard is random. The shape of the selected radical symbols cannot be associated with that of English alphabets, so its application is limited for local use only.
The following method and apparatus generates collision-free character coding for Chinese input and text communication employing conventional keyboards. It also provides means for maintaining characters found in a document or a data base file in a consistent and unique code for communication between different systems having the same coding schemes.